(NBC News) Police in Ferguson, Missouri abruptly backed off plans Tuesday to release the identity of the officer who shot and killed an unarmed teenager over the weekend.

The shooting sparked three days of sometimes violent protests.

“We just don’t think it’s safe right now,” Ferguson Police Chief Tom Jackson said. “It’s a minority of people that are making the threats, but we think right now some may be credible, so we are going to delay that information”

The chief’s decision didn’t set well with the family of victim Michael Brown, Jr., but they again called for calm at a rally Tuesday afternoon.

“I need all of us to come together and do this right, the right way. The right way so we can get something done about this, no violence!” said Michael Brown, Sr.

The plea followed a second straight night of unrest. On Monday night officers in riot gear lobbed tear gas at crowds angered by Brown’s death and more than dozen people were arrested.